Synedrean haven defense. Had to defend multiple structures. One enemy left (mind fragger it glitched either into a broken chair or into the ground beneath said chair. Really need to know if i can fix it wothout reset/redoing the mission i had to fight an army of sirens, heavily armored explosive arthrons, and i mind fragger spawner boss, i killed them all first try without losing a single unit, really need to know how i can fix it. (Am out of grenades, heavy is out of ammo, and the archnids bombs i threw out next to the chair keep climbing the building above said chair then exploding without destroying the chair, small arms fire wont destroy the chair either) HELP!!! Plz
Hey, Tigerbloodxninja.
Sorry to hear you’ve encountered this issue. The game has a bug reporting system, so if you load up the save and hit F12, the game will take a screenshot (centre the screen on the problem enemy that’s clipped through the level geometry) and save some other information. Copy the text you wrote above into the text box and send it to the developers (there’s a button on the screen in the bug report).
I don’t know if this will help your exact sitation but the developers will be able to use the information to hopefully stop it from happening again in future.
Unfortunately, I don’t have any advice on how to proceed with the problem. 
Kk next time it happens i will and thank you